Crevice guard for horizontally disposed rotary sewing hook

ABSTRACT

A crevice guard for covering the crevice between the hook piece and hook body of a horizontally disposed rotary sewing hook to prevent the thread from becoming caught in the crevice and torn or interrupted in its movement during a stitching cycle.

United States Patent [72] Inventor Samuel Armao [56] References Cited447 S. Fifth 51., Reading, Pa. 19602 UNITED STATES PATENTS 1 988 7891/1935 Grieb 112/228 x 122] Filed 1970 2 209 906 7 1940 R b 1 1 2 22s 45Patented Oct. 12, 1971 l 2 2,435,358 2/1948 Kessler... 112/228 2,716,9569/1955 Parry 112/230 3,223,060 12/1965 Corey 112/228 PrimaryExaminerA1fred R. Guest 541 CREVICE GUARD FOR HORIZONTALLY AmmekshmmakerDISPOSED ROTARY SEWING HOOK 7 Claimsfinrawmg Flgs' ABSTRACT: A creviceguard for covering the crevice [52] 11.5. C1 112/228 between the hookpiece and hook body of a horizontally [51] 1nt.C1 D05b 57/14 disposedrotary sewing hook to prevent the thread from [50] Field of Search. 112/228, becoming caught in the crevice and torn or interrupted in its230 movement during a stitching cycle.

PATENTED 0m 1 219m 3611.962

FIG. I. F/6.Z.

(PRIOR ART) INVENTOR SAMUEL ARMAO ATTORNEYS CREVICE GUARD FORHORIZONTALLY DISPOSED ROTARY SEWING HOOK BACKGROUND OF THE INVENTIONThis invention relates generally to horizontally disposed rotary sewinghooks of the type used in lockstitch sewing machines.

Prior art horizontally disposed rotary sewing hooks have a crevice orgap between the hook piece and the hook body of the tdtary sewing hookin which the thread frequently becomes snagged or torn as it passesupwardly from the bobbin held in the hook body as the hook body rotatesduring a stitching cycle. This snagging or interference with themovement of the thread during a stitching cycle results in uneven orimproper stitches and frequently the thread is broken, necessitatingshutdown of the machine in order to rethread the device resulting inloss of working time and increased production costs due to the loss ofproduction time and the fact that a paid mechanic or operator must beemployed to rethread the machine. Further, articles being stitched inthe machine are caused to be improper or imperfect due to faultystitches caused by snagging of the thread.

The present invention provides a simple and economical guard over thecrevice in horizontally disposed rotary sewing hooks to prevent thethread from becoming snagged or torn therein, thus significantlyreducing loss of time and operating expenses frequently occurring inprior art machines which do not have any means for covering or guardingthe crevice in the rotary sewing hook.

OBJECTS OF THE INVENTION It is an object of this invention to provide arotary sewing hook having a crevice guard placed over the crevice or gapbetween the hook piece and the hook body to prevent thread from becomingsnagged or torn therein.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a side view in elevation ofa prior art rotary sewing hook showing the crevice between the hookpiece and hook body.

FIG. 2 is an exploded side elevational view of a first modification ofthe invention showing the crevice guard on the hook piece extended intoa slot in the hook body and covering the crevice.

FIG. 3 is an exploded side view in elevation of a second modification ofthe invention showing the crevice guard on the hook piece and extendedover the crevice onto a sloping surface on the hook body.

FIG. 4 is a side view in elevation of a third modification of theinvention showing the crevice guard attached to the castoff piece andextended over the crevice onto the hook piece.

FIG. 5 is a perspective view of the crevice guard which is affixed tothe castofi piece in the embodiment illustrated in FIG. 4.

FIG. 6 is a top perspective view of the embodiment illustrated in FIG.3, illustrating the manner in which the crevice guard overlies thecrevice between the hook piece and hook body.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawingswherein like reference numerals refer to like parts throughout theseveral views, a conventional horizontally disposed rotary sewing hookis indicated generally at 1 in FIG. 1. The rotary sewing hook comprisesa hook body 2 and a hub portion 3 whereby the rotary sewing hook may beaffixed to a rotary hook shaft (not shown) by means of the setscrews 4.A generally semicircular thread retainer or hook piece 5 is affixed tothe outer sidewall on one side of the hook body by means of screws 6 anda generally semicircular castoff piece or gib 7 is affixed to theopposite outer sidewall of the hook body by means of screws 8. As

clearly illustrated in this figure, a crevice or gap 9 is left betweenthe hook piece 5 and the hook body 2 and in operation, a thread passingupwardly from a bobbin case holder (not shown), normally disposed in andcarried by the rotary sewing hook, tends to become caught or snagged inthe crevice thus causing improper stitches to be made and frequentlynecessitating shutting down of the machine.

Referring now to FIG. 2, a first modification or form of the inventionis depicted and comprises an elongated narrow lip or extension 10 weldedat one end 10a into a shallow notch or recess 11 formed in the marginaledge portion of the hook piece 5 and extending at its other end 10b intoa short notch or slot 12 in the hook body 2. The lip or extension 10constitutes a crevice guard effectively covering the crevice 9 thuspreventing thread from being caught therein. The castoff piece or gib 7is removed from the hook body in these figures so that the relationshipof the extension 10 and slot or notch I2 in the hook body can be seen.

Referring now to FIGS. 3 and 6, a second modification of the inventionis illustrated and is similar to the embodiment il- Iustrated in FIG. 2.In this modification, the lip or extension comprises a relatively narrowelongated member I0 having one end 10a welded in a shallow notch orrecess 11 in the hook piece 5 as in the previous embodiment. In thismodification, however, the end 10b of the extension is upwardly inclinedand rests in mating abutting relationship on a sloping surface 13 on thehook body 2 rather than being extended into a slot or notch 12 as in theprevious embodiment. The castoff piece or gib 7 is shown removed in thisfigure also in order that the relationship of the extension 10' with thecrevice 9 and sloping surface 13 on the hook body may be clearly seen.Referring now to FIGS. 4 and 5, a third modification of the invention isillustrated and comprises an irregularly shaped plate or member 14having a narrow elongate extension 15 on one side thereof welded orotherwise secured to the castoff piece or gib 7 as at W with theextension 15 extended over the slot or crevice 9 and resting in flatabutting relationship on the edge of hook piece 5. The plate 14 isground or otherwise formed so as to define a smooth configuration withthe outer surface of the castoff piece 7 and is substantially flushtherewith in the vicinity of the weld W so as not to present any unevensurfaces on the rotary sewing hook.

The present invention thus provides a simple and effective crevice guardfor covering the crevice between the hook piece and hook body of arotary sewing hook to prevent thread from becoming snagged or torn inthe crevice during a stitching cycle of the rotary sewing hook.

As this invention may be embodied in several forms without departingfrom the spirit or essential characteristics thereof, the presentembodiment is therefore illustrative and not restrictive, since thescope of the invention is defined by the appended claims rather than bythe description preceding them, and all changes that fall within themetes and bounds of the claims or that form their functional as well asconjointly cooperative equivalents, are therefore intended to becmbraced by those claims.

I claim:

I. A horizontally disposed rotary sewing hook for lockstitch sewingmachines comprising a hook body having a hook piece secured thereto andslightly spaced at one end from the hook body to define a relativelynarrow gap or crevice between the hook piece and the hook body, andcrevice guard means fixed to said rotary sewing hook in overlyingrelationship with said crevice to prevent thread from being snagged orcaught in said crevice during a stitching cycle of said rotary sewinghook.

2. A horizontally disposed rotary sewing hook as in claim I, whereinsaid crevice guard means is fixed to said hook piece adjacent saidcrevice and comprises an extension on said hook piece extended over saidcrevice.

3. A horizontally disposed rotary sewing hook as in claim 2, whereinsaid crevice guard means comprises a relatively narrow elongate lip orextension fixed to a marginal edge portion of said hook piece andextended over said crevice.

4. A horizontally disposed rotary sewing hook as in claim 3, whereinsaid crevice guard means is welded at one end to said hook piece andextends at its other end generally circumferentially away from said hookpiece over said crevice and into a slot formed in said hook body 5. Ahorizontally disposed rotary sewing hook as in claim 3, wherein saidcrevice guard means extends generally circumferentially away from saidhook piece and is upwardly inclined at one end portion thereof and restsin mating abuttingrelationship at said one end portion on a slopingsurface on said hook body.

6. A horizontally disposed rotary sewing hook as in claim 3, wherein acastoff piece is fixed to said hook body adjacent said hook piece andsaid crevice guard means is fixed to said castoff piece.

7. A horizontally disposed rotary sewing hook as in claim 6, whereinsaid crevice guard means is fixed to an end portion of said castoffpiece and includes a relatively narrow elongate lip extended away fromsaid castoff piece toward said hook piece in overlying relationship tosaid crevice.

1. A horizontally disposed rotary sewing hook for lockstitch sewingmachines comprising a hook body having a hook piece secured thereto andslightly spaced at one end from the hook body to define a relativelynarrow gap or crevice between the hook piece and the hook body, andcrevice guard means fixed to said rotary sewing hook in overlyingrelationship with said crevice to prevent thread from being snagged orcaught in said crevice during a stitching cycle of said Rotary sewinghook.
 2. A horizontally disposed rotary sewing hook as in claim 1,wherein said crevice guard means is fixed to said hook piece adjacentsaid crevice and comprises an extension on said hook piece extended oversaid crevice.
 3. A horizontally disposed rotary sewing hook as in claim2, wherein said crevice guard means comprises a relatively narrowelongate lip or extension fixed to a marginal edge portion of said hookpiece and extended over said crevice.
 4. A horizontally disposed rotarysewing hook as in claim 3, wherein said crevice guard means is welded atone end to said hook piece and extends at its other end generallycircumferentially away from said hook piece over said crevice and into aslot formed in said hook body.
 5. A horizontally disposed rotary sewinghook as in claim 3, wherein said crevice guard means extends generallycircumferentially away from said hook piece and is upwardly inclined atone end portion thereof and rests in mating abutting relationship atsaid one end portion on a sloping surface on said hook body.
 6. Ahorizontally disposed rotary sewing hook as in claim 3, wherein acastoff piece is fixed to said hook body adjacent said hook piece andsaid crevice guard means is fixed to said castoff piece.
 7. Ahorizontally disposed rotary sewing hook as in claim 6, wherein saidcrevice guard means is fixed to an end portion of said castoff piece andincludes a relatively narrow elongate lip extended away from saidcastoff piece toward said hook piece in overlying relationship to saidcrevice.